Positive Sequence Resistance and Reactance calculation

a) Maximum three phase fault current in amperes (A) and phase angle in degrees (B).

I want to calculate the positive sequence resistance (R) and reactance (X) from above two variables for a symmetric system. I couldn't figure out a way to find R and X values using just these two parameters. However I noted somebody has calculated them using following formula for same purpose (unfortunately couldn’t verify who did this in my workplace).

R = A * COS ( PI()*B/180 ) X = A * SIN ( PI()*B/180 ) where A is the three phase fault current and B is the phase angle

If someone can assist me to figure out the correct formula and the relation above, please